Hosea e



(No Model.)

- H. R. 'T-ILLISON.

/ REAMER.

Patented Sept. 28, 1886.

M. d 1 m w W W I d a frustum of a cone.

- UNITED STATES PATENT OFFICE.

HOSEA R. TILLISON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO S. A. WOODS MACHINE COMPANY, OF SAME PLACE.

REAMER.

SPECIFICATION forming part of Letters Patent No. 349,766, dated September 28, 1886.

Application filed November 23, 1885.

To all whom it may concern:

Be it known that I, HOSEA R. TILLISON, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Reamer-s, of which the following is a specification.

My invention relates to reainers for reaming or enlarging holes in metal and other simicylindrical portion, a,and on one end of this is turned a tapering spindle, a, in the form of On theend of this spindle is formed a screw-thread, a, and where the spindle joins the cylindrical portion of the reamer the shoulder between them is undercut all around, as shown at a. A nut, n, is fitted to the screw-thread a, and has its inner face undercut in the same manner.

To construct the cutting portions of the tool a cylinder of steel is formed with the cutters b longitudinal upon its surface, with a tapering bore through its central portion corresponding-with the tapering spindle a, and this cylinder is divided by longitudinal slits b into three or more portions, 1), and the ends of these portions are beveled off to correspond with the beveled faces of the nut n and the undercut shoulder a, respectively. The segments of the cylinder 1) are next assembled around the spindle a, and the nut 11. is set up firmly 7 Serial No. 183,668. (No model.)

against them, binding them within its beveled face at that end and forcing their opposite ends into the under-cutot' the shoulder a, thus firmly securing them upon the spindle and adjusting them in proper position for use. By this construction. I am enabled to make the cutters much stronger, where formed in groups of two or more upon the segments of cylinder I), than where they are made separately, and.

by starting the nut n backward I. am enabled to remove and rcgrind or replace them with new ones at less expense than when the entire reainer has to be made new when worn. I also am enabled to very readily expand the cutters whenever they are worn, so as to inaterially diminish the diameter of their cutting-edges by simply turning out the undercut shoulder a in a lathe or by grinding off the upper bevel of each segment I), which fits into this shoulder.

In Fig. 4 the shoulder a is shown as formed upon a nut, a, similar to the nutn, which nut is capable of being screwed upward upon the reamenbody, thus allowing the lower nut, n, to force the segments of the cylinder 1) further upward upon the tapering spindle a and enlarging their diameter.

What I clainras new and of my invention 1s The reainer A, formed with the tapering spindle a, the undercut shoulder (1 the thread a", and the nut n, in combination with the segments of a cylinder, I), eachprovided with two or more longitudinal cutters, 1), upon its exterior and with beveled ends, substantially as described.

HOSEA R. TILLISON. 

